In manufacturing bodies for vehicles such as trucks, cars and buses, panels of sheet metal have been structurally secured together by placing a ribbon of a plastic epoxy resin between overlapped portions of the panels. Typically, the resin is a one stage resin which is cured to bond the panels together by heating it only once to an elevated temperature for a substantial period of time to fully cure the resin. The resin has been cured by heating the whole assembly by passing it through a paint baking oven or by somewhat localized heating of substantial portions of the assembly with infrared lamps or the direct flame of gas torches. All these approaches require several minutes to heat the assembly sufficiently to fully cure the one stage resin. Moreover, this localized heating or cooling of the assembly or even rapid heating or cooling of the entire assembly tends to significantly warp or distort the panels of the assembly. This distortion can only be partially controlled by firmly or rigidly clamping in fixtures the panels adjacent the ribbon of epoxy. These fixtures also accurately locate the sheet metal panels until they are structurally bonded together by the cured epoxy resin.
If the sheet metal assembly is bare or unpainted, this heating to cure the resin also results in sufficient oxidation of the metal so that subsequently applied paint will not adequately adhere to the metal. Consequently, when a painted assembly is required, either the bonded sheet metal assembly must be cleaned or otherwise processed to remove the oxidation and then be painted or be painted before being heated to cure the epoxy. However, if the sheet metal assembly is painted before the epoxy is cured, it must be handled carefully to prevent the panels of the assembly from shifting or moving so that they are inaccurately located relative to each other. In many applications, the need to accurately locate the sheet metal panels of the assembly and/or to rigidly clamp them during heating, means that with many assemblies and in many manufacturing processes and applications, it is impractical or impossible to bond the resin to structurally secure together panels after they have been painted.